Steam-generator.



H. C. CALDWELL.

STEAM GENERATOR.

APPLICATION man ocT.15. 1911` Patented July 4, 1916.

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H'. c. CALDWELL. STEAM GENERATOR.A

APPLICATION FILED OCT. I6. ISII.

Patented July 4, 1916.

2 SHEETS-SHEET 2.

ATTQRNEY UNTTED sTATEs PATENT union g HENRY C. CALDWELL, OF BUFFALO, NEW YORK, ASSIGNOR TO J. W. DANIELS, TRUSTEE,

OF PHILADELPHIA, PENNSYLVANIA, y

@EAM-GENERATOR.

Specification of Letters Patent.

Patented. July 4, 1916.

Application filed October 16,1911. Serial No. 655,033.

To all whom t may concern Be it known that I, HENRY C. CALDWELL, a citizen of the United States of America, residing at Buffalo, in the county of Erie and State of New York, have invented certain new and useful Improvements in Steam- Generators, of which the following is'a full, clear, andV exact description.

My invention relates generally to steam generators but more particularly to that class of generators in which the steam leaves the steam generating pipes just as soon as it is generated.

In the steam generators of the prior art, a very large portion of the heat from the coal goes up the chimney ofthe-furnace and another large portion thereof is also lost by radiation.

In producing my invention the general object has been to provide a steam generator which shall be economical in fuel consumption and one which shall utilize as far as possible all of the units of heat that are ordinarily lost by passing up the chimney and also those which are lost by radiation.

Another object of my invention has been to provide a generator in which there shall be little or no danger of explosion and one in which, should the boiler by any means give way, the result would be nothing more than the escape of steam within the central portion of the generator which would in no wise be dangerous.

As is well known, to secure the best available economy in fuel consumption, the fuel must be burned rapidly and at a high temperature.

To accomplish the above objects and ad' vantages, I provide a very'small heating surface with a large firewhichis supplied withl air under pressure. The air is heated to aH high temperature before it is ,forcedinto the twyer and the water is heated before it is' forced into the steam generating pipes. Furthermore my generator is automatic in its regulation and is so constructed that it may be charged with fuel suflicient for a definite length of time during which it shall require no attention whatever. i

Reference is to be had to the accompanying drawings in which like characters of reference indicate like parts throughout the several views of which: e Y l Figure 1 is ay vertical sectional elevation taken through the center of the generator.

casing.

Fig. 2 is a sectional elevation taken on line A. B of Fig. 1 and shows a quantity of fuel in place in the generator. Fig. 3 is a side elevation of the generator together with its accessories and the necessary piping connected thereto. j Y

Referring now to the drawings and more particularly to Figs. 1 and 2, 4 is myv steam generator and 5 is the outside casing or water tank thereof, within which are secured two preferably diamond shaped casings 6 and 7; an air casing 6 and a furnace casing 7 spaced apart. VThese casings 6 and 7 extend longitudinally from-end to end of the water casing 5 and are secured at the ends thereto. The furnace casing 7 is somewhat smaller than the air casing 6 and is disposed within said air casing 6 thereby providing an air space 8 surrounding the furnace casing 7.l lcompressed air inlet 45 leads into the air space 8. On the interior of the furnace casing 7 and also that portion of the water casing heads which is inclosed by said furnace casing 7, is provided a refractory lining 9. Disposed within the furnace casing 7 and preferably close to the refractory lining is a diamond shaped steam generating coil `10'provided with an inlet 11 and an outlet 12 conforming to the interior dimensions of the furnace casing 7. Obviously for this coil there lmay be substituted a plurality of pipes running into manifolds and the same results accomplished. Secured to the front and rear ends of the water tank are hollow heads 13 and 14 each having a jacket 15 and thus providing waterspaces 16. The front head 13 is'provided with a stoke hole 17 and a coal hopper l8ilocated preferably at substantially the center of the furnace A cleaning out hole 19 is also provided through which the clinkers and ashes may be removed vfrom the furnace. The heads'l and14 are provided vwith water inlet pipes 41 and 42 respectively at the bottom and suitable :discharge pipes`43 and 44 which carry the water from they said heads and into the top of the water'tank 5. Disposed within the furnace casing 7 Vand near the converging bottom is a twyer 20. This twyer ter of the furnace casing is a vent pipe 22, which is provided with two branches or T connections 23 and 24 and between these branches with a valve 25. The connection between the two Ts 23 and 24 forms simply a by-pass of S shape for the gases coming from the fire and by which the water in the tank 5 may be made to circulate and be partially heated. This may be carried out by any suitable means of connection but preferably as shown. As shown the T 24 has eX- tending therefrom an elbow 26 upon which is secured a valve 27. 28 is a return bend which is secured at one end to the valve 27 and which is secured at the other end to an elbow 29. rlhe elbow 29 has a short horizontal pipe 30 extending therefrom which has at its outer end a T 31 to which is secured an upwardly turned elbow 32 on the horizontal run and a long vertical downwardly extending pipe 33 secured to the depending branch of said T. Rising vertically from the elbow 32 is a short pipe 34 which has secured at its upper end an elbow 35. Secured to the elbow 35 is a T 36 with its branch turned upwardly which is connected to the branch of the T 23 by means of the piping 37 and 38 and elbow 39. The inner end of the T 36 has preferably secured thereto a downwardly projecting elbow 40. The valves 25 and 27 may be of any suitable construction and are preferably lined with refractory material to protect them from the heat of the escaping gases. These valves are preferably so located as to be beneath the water level in the water tank 5 and are provided preferably with long stems which project through the casing of the water tank, thus making them easily operable from the outside of the tank.

Referring now to Fig. 3; 4 is the generator; 46 is an equalizer or expansion tank which is supplied. with water under pressure by means of the steam pump 47. The water is drawn by the pump from the water tank of the generator through the piping 48 and 49 and is forced into the equalizer through the pipe. 50 and from said equalizer the water is carried to the inlet of the steam coil by means of the pipe 51. A valve 52 is preferably placed in the pipe 51 whereby the supply of water to the generating coil may be shut off when desired. A water gage 53 is preferably provided on the equalizer to indicate the height of the water in the same. When in operation the upper part o-f the equalizer is filled with air, thus providing a cushion and means for eXpansion for the entering water. A safety valve 54 is provided in the upper part of the equalizer. 55 is the water supply valve, the water from the mains being carried to the inlet 41 and 42 of the casing heads by means of suitable piping as shown. 56 is a steam header in which the steam is forced before it is carried olf by the steam main 57. This header 56 is connected to the outlet 12 of the steam generating coil by means of the piping 58. In the piping is preferably placed a valve 59, a steam gage 60 and a safety valve 61. Connecting the steam pump 47 with the steam main 57,is a line of steam piping 62 and in the pipe line is placed a valve 63 and a pressure reducing valve 64, whereby the steam pressure in the steam cylinder of the pump may always be kept constant. Connecting with the compressed air inlet 45 is a line of piping 65 in which is inserted a valve 66 controlled bv a dampening device 67. Piping 68 connects the steam main 57 with the cylinder of the dampening device. 69 is a steam trap which takes care of the condensation in the steam header 56. Piping 70 carries the condensation from the trap and discharges it preferably into the top of the water tank of the generator.

Having thus described my invention I willnow describe its operation:

When it is desired to operate my generator the furnace casing 7 is filled with sufficient coal to last approximately the length of time it is desired to run, the fire lighted and the blast applied to the twyer. The valve 27 is closed and the valve 25 open at this time. After the fire has become well started the valve 25 is closed and the valve 27 opened. Instead of the hot gases escaping up the vent they are now by-passed and made to pass through the elbow 26, valve 27, return bend 28, elbow 29, pipe 30, T 31, elbow 32, pipe 34, elbow 35, T 36, pipe 37, elbow 39, pipe 38 and into the vent 22. As these gases pass through the above mentioned ttings they cause a suction in the pipe 33 which raises the cold water in the lower part of the tank and discharges it through the elbow 40 into the top of the tank, thus not only causing a circulation of the water in the tank but also utilizing all of the heat units in the said hot gases before they go up the vent. The return bend 28 is made high enough so as to preclude the possibility of any water running from the tank into the furnace. The heat which radiates from the sides of the furnace is made to heat the water in the tank by reason of -it being surrounded by said water and the heat which radiates from the ends of the furnace is made to heat the water which enters the heads direct from the mains. The compressed air enters the air space 8 and is conducted from there to the twyer by the piping 21, thus the air is also heated before being blown beneath the fire. As the hot water is forced into the steam generating coil 10 it is immediately generated into steam and carried to the header 56 and into the steam main 57. As the steam pressure in the main decreases or increases from normal, the dampening device will operate the valve 66 to either increase or decrease the amount of air being forced into the twyer, as the case may be, thus regulating the heat of the fire and the resulting steam pressure. It is understood of course that the steam header 56 acts also to take care of any slight'fluctuation in the steam pressure as it is generated and thus it, together with the dampening device, keeps the steam pressure in the main 57 constant.

lVhen it is desired to clean out the furnace after it has been running a specified length of time, the twyer 20 being held and connected in a detachable manner, is withdrawn and the ashes and clinkers removed through the opening 19. Of course if desired I may extend the clean-out hole 19 lower down thus making it possible to remove the ashes and clinkers from the furnace without having first to Withdraw the twyer 20.

As shown in Fig. 3, I am using accessories well known in steam engineering and obviously I may use any other accessory or any other arrangement of the same which will give the equivalent result and also many modified details of construction in my steam generator, as shown and described, may be made without departing from the spirit of my invention and I do not Wish to be limited to the exact embodiment herein shown and described. c

Having thus described my invention what I claim is:

1. A steam generator comprising a furnace casing, a steam coil within said furnace casing, a water tanksurroundng said furnace casing, means for carrying the water in said watertank to said steam coil, a vent rising from said furnace casing, and a lay-pass in said vent, partly submerged in the water in said tank; the heat units radiating from said furnace casing and the heat units in the gases passing up the vent being utilized to heat the water before it is passed to the steam coil to be generated into steam.

2. A steam generator comprising a furnace casing, a steam coil within said furnace casing, an air casing providing an inclosed air space lsurrounding said furnace casing, a twyer disposed in said furnace casing within said steamcoil, means for conducting compressed air to said air space, means for carrying air from the air space to the said twyer, a water tank surrounding said furnace casing and said air casing and means for carrying the water in said water tank to said steam coil.

3. A steam generator comprising a furnace casing, a steam coil within said furnace casing, an air casing providing an inclosed air space surrounding said furnace casing, atwyer disposed in said furnace casing within said steam coil, means for conducting compressed air to said air space, means for carrying air from the air space to the said twyer, a water tank surrounding said furnace casing, a vent rising from said furnace casing, a by-pass in said vent, partly submerged in the water in said water tank, and means for carrying the water in said Water tank to said steam coil.

4. A steam generator comprising a water tank, a furnace casing within the water tank, a steam coil within the furnace casing conforming to the interior dimensions of the furnace casing, an air casing surrounding the furnace casing and spaced therefrom so as to provide an air chamber, a twyer within the furnace casing and the steam coil, a pipe conducting compressed air to the air chamber, a pipe conducting air from the air chamber to the twyer, a vent pipe from the furnace chamber having a bypass, partly submerged in the water tank, and provided with a downwardly extending pipe conducting water from the lower part of the tank to the by-pass which dischargesV the same into the upper part of the water tank, through the suction of the gases passing through the by-pass.

5. A steam generator comprising a water tank, a furnace casing of diamond shape within the water tank, a steam coil of diamond shape within the furnace casing conforming to the interior dimensions of the furnace casing, an air casing of diamond shape surrounding the furnace casing and spaced therefrom so as to provide an air chamber, a twyer within the furnace casing and the steam coil, a pipe conducting compressed air to the air chamber, a pipe conducting air from the air chamber to the twyer, a vent pipe from the furnace chamber having a by-pass of S shape, partly submerged in the water tank, and provided with a. downwardly extending pipe conducting water from the lower part of the tank to the by-pass which discharges the same into the upper part of the water tank through the suction of the gases passing through the by-pass.

In testimony whereof, I have hereunto set my hand in the presence of two witnesses.

HENRY C. CALDWELL.

Witnesses:

J. WM. ELLIS, WALTER H. KELLEY.

Copies of this patent may be obtained for vc cents each, by addressing the Commissioner or Intenta Washington, D. G. 

